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Comment · 8 years ago
One main point to take for the analyses is that photons are bosons, so they don't interact between each other, which makes optical switches a pretty hard thing to do.

What we do is using interference to make a switch. More specifically, we use an apparatus called Mach-Zehnder interferometer (combined with a phase shifter) to manipulate the light.

Comment · 8 years ago
Not even close.

Photonics chips and programable photonics are not a way to substitute conventional electronics, but a replacement/complement for some areas of the field where electronics is not efficient.

Comment · 8 years ago
I'll try an ELI5:

When the light propagates in a waveguide as the one used in my circuit, the E and H components of the EM wave are not fully confined to the waveguide, but part of it stays outside the waveguide. If you put two waveguides close to each other and makes the light travel to the first waveguide, part of the EM field of the light will also see the second waveguide.it makes part of the ligh couple to the second waveguide. As the wave travels, more and more light couples to the second waveguide. If you engineer it well, at some point 50% of the light will be confined in each waveguide. At this point you separate both WG and you have a 50:50 coupler.

Comment · 8 years ago
The concept of speed that we use in a digital computer does not automatically applies to our optical circuit once we don't work using cycles of a clock. It's not a digital computer, but an operator that realizes a linear operation on an input. The speed of this operation is only bounded by the speed of the light propagating though the circuit.

We have optical chips in operation everywhere for decades, that's not something new. An programmable optical chip has been demonstrated by different research groups, and, for some limited applications, I do believe that we will have it in the marked in 7 to 10 years.

We are also working on different topologies besides the one mentioned in the paper.

Comment · 8 years ago
I don't see photonics doing the data processing anytime soon. For that our current electronics works just fine.

What we do with photonics is to improve areas where the electronics is not efficient.

Case and point: interconnections. If you want to move data from point A to point B (being A and B either two different chips in your board our two datacenters), we can do it using electric signals, it works just fine, but at some cost. Electric signals dissipate power when they travel through a conductor, no matter how good the conductor is.

If instead we use optical signals instead of electrical, we have advantage in a number of points, specially power efficiency.

Comment · 8 years ago
Hi,

Photonics ICs are all around. You can find it in many different applications, but mostly in datacom and telecom.

A very simple example: anywhere you have a optical fiber you also need a photonic IC to, at least, convert the light into electrical signal to interface your electronics (and vice-versa).

What we are doing with photonics is adding more functionality in the optical part (filtering signal, multiplexing, modulation, etc) once, in mostly cases, it's more efficient doing that in the optical domain instead of using electronics.

Comment · 8 years ago
The full optical device is no bigger than 1mm x 0.5mm. It's very tiny in total size.

The point here is that our current implementation has a limited IO capability (our linear operator has 4 inputs and 4 outputs), but increasing the number of IOs leads to a linear increase in the size of the device.

Comment · 8 years ago
Comment · 12 years ago
tks
Comment · 13 years ago
This is as much cute as useless.
Comment · 13 years ago
I really like ST, it is the first text editor that I use for more than 1 year in a row.

But 70 Dollars is really expensive in my point of view. I'm not sure if I'll upgrade to version 3 (paying upgrade).

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